Loans Receivable, Net (Details) (USD $) In Thousands, unless otherwise specified	3 Months Ended		9 Months Ended
	Sep. 30, 2012	Sep. 30, 2011	Sep. 30, 2012	Sep. 30, 2011
Allowance for loan and lease losses
Balance at beginning of period	$ 137,459	$ 139,795	$ 137,516	$ 137,107
Provision for loan losses	2,700	17,175	19,250	55,825
Charge offs	(5,052)	(19,980)	(24,789)	(58,298)
Recoveries	1,553	1,103	4,683	3,459
Balance at end of period	136,660	138,093	136,660	138,093
Residential Real Estate [Member]
Allowance for loan and lease losses
Balance at beginning of period	18,139	17,412	17,227	20,957
Provision for loan losses	209	2,846	2,294	2,143
Charge offs	(1,172)	(1,030)	(2,492)	(4,187)
Recoveries	73	35	220	350
Balance at end of period	17,249	19,263	17,249	19,263
Commercial Real Estate [Member]
Allowance for loan and lease losses
Balance at beginning of period	79,098	79,885	76,920	76,147
Provision for loan losses	(1,210)	9,729	11,800	33,426
Charge offs	(586)	(14,531)	(13,120)	(35,850)
Recoveries	453	607	2,155	1,967
Balance at end of period	77,755	75,690	77,755	75,690
Other Commercial [Member]
Allowance for loan and lease losses
Balance at beginning of period	20,570	19,615	20,833	19,932
Provision for loan losses	2,859	2,399	4,163	9,006
Charge offs	(1,441)	(1,557)	(3,797)	(8,723)
Recoveries	241	166	1,030	408
Balance at end of period	22,229	20,623	22,229	20,623
Home Equity [Member]
Allowance for loan and lease losses
Balance at beginning of period	10,904	13,625	13,616	13,334
Provision for loan losses	(555)	1,444	(1,025)	3,859
Charge offs	(1,044)	(1,448)	(3,402)	(3,751)
Recoveries	679	225	795	404
Balance at end of period	9,984	13,846	9,984	13,846
Other Consumer [Member]
Allowance for loan and lease losses
Balance at beginning of period	8,748	9,258	8,920	6,737
Provision for loan losses	1,397	757	2,018	7,391
Charge offs	(809)	(1,414)	(1,978)	(5,787)
Recoveries	107	70	483	330
Balance at end of period	$ 9,443	$ 8,671	$ 9,443	$ 8,671